Convective Heat Transfer in Vertical Eccentric Annulus with Rotating Inner Cylinder
Abstract
The natural, forced and mixed convection heat transfer process in vertical eccentric open ended and opened upper end annulus with stationary and rotating inner shaft and uniformly heated stationary outer cylinder has been experimentally investigated. The study covers a wide ranges of heat flux 80 q 500 W/m2, rotational Reynolds number =0 (stationary inner shaft) and 50 100 for laminar Couette flow ( ), and 150 300 for turbulent Taylor vortex flow, and Richardson number 0.23 Ri 30. The results showed that the heat transfer process improves as the eccentric ratio increases, and the heat transfer process in open ended eccentric annulus is better than that in opened upper end eccentric annulus by 7.5 %. Four empirical correlations for average Nusselt number (Num) have been deduced as a function of and Ra for pure natural convection and as a function of and Ri, for mixed convection. The results are compared with previous works and show a good agreement.
